The Dual Antiplatelet Therapy Trial after the FDA Update: Noncardiovascular Deaths, Cancer and Optimal Treatment Duration

Abstract

Background: The landmark Dual Antiplatelet Therapy (DAPT) trial revealed an impressive reduction of stent thrombosis and myocardial infarction after prolonged 30-month DAPT compared to the conventional 12-month regimen. However, aside from the expected extra bleeding risks, more cancers and noncardiovascular deaths (NCVD) were observed in the 30-month DAPT arm. Objective: We aimed to comprehend the totality of DAPT trial evidence in the light of the FDA medical review. Results: A significant excess of solid cancers that was picked up after prasugrel treatment in the TRITON trial (Prasugrel versus Clopidogrel in Patients with Acute Coronary Syndromes) and later observed with vorapaxar treatment in the TRACER trial (Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome) has now been confirmed by the FDA DAPT review for 30-month therapy with prasugrel [hazard ratio (HR) 1.3] and clopidogrel (HR 1.2). The latest randomized evidence with antiplatelet agents rejected the drug-specific cancer risks, clearly indicating the class effect. The NCVD risks were elevated after treatment with both thienopyridines, but were more prominent after clopidogrel treatment (HR 1.91) than prasugrel treatment (HR 1.17). About half of the NCVD were considered to be caused by cancers occurring after the 24 months of extended antiplatelet therapy. Impression: The DAPT trial confirmed that long-term antiplatelet therapy is associated with cancer that contributes to NCVD. Based on the full disclosure of cancer data by the DAPT study, it can be reflected that the optimal duration of antiplatelet therapy with thienopyridines should be limited to no more than 2 years. This duration allows the preservation of most vascular benefits while avoiding additional cancers and NCVD.